This study presents the results of transcutaneous oxygen pressure (TcPO2) monitoring during a treadmill test walk performed in the early stages of peripheral obliterative vascular disease. The study population consisted of a first group of 50 known arteriopathic patients presenting, on questioning, with intermittent claudication; a second group of 50 known arteriopathic patients void of any symptoms of intermittent claudication; and a third group, which was a control cohort of 20 nonarteriopathic, nonclaudicating patients. Though resting TcPO2 cannot be used to aid the clinical diagnosis of exercise ischemia it may be useful in revealing asymptomatic chronic resting ischemia (9% of cases in this series). On the other hand, a posteffort (recovery phase) fall in TcPO2 had a predictive positive diagnostic accuracy for ischemia on exercise in 99% of the cases reported here versus 87% for clinical appraisal. In the light of these results, TcPO2 measurements coupled to a treadmill test walk perfectly ascertain exercise ischemia in arteriopathic patients, whether asymptomatic or not, and avoid the false-positive results obtained by clinical evaluation.